Erden Fuat, Li Hui, Wang Xizu, Wang FuKe, He Chaobin
Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117576, Singapore.
Polymeric Materials Department, Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore.
Phys Chem Chem Phys. 2018 Apr 4;20(14):9411-9418. doi: 10.1039/C7CP07896J.
In the present work, we report the fabrication of high-performance thermoelectric materials using TiO2/CNT/PANI ternary composites. We showed that a conductivity of ∼2730 S cm-1 can be achieved for the binary CNT (70%)/PANI (30%) composite, which is the highest recorded value for the reported CNT/PANI composites. We further demonstrated that the Seebeck coefficient of CNT/PANI composites could be enhanced by incorporating TiO2 nanoparticles into the binary CNT/PANI composites, which could be attributed to lower carrier density and the energy scattering of low-energy carriers at the interfaces of TiO2/a-CNT and TiO2/PANI. The resulting TiO2/a-CNT/PANI ternary system exhibits a higher Seebeck coefficient and enhanced thermoelectric power. Further optimization of the thermoelectric power was achieved by water treatment and by tuning the processing temperature. A high thermoelectric power factor of 114.5 μW mK-2 was obtained for the ternary composite of 30% TiO2/70% (a-CNT (70%)/PANI (30%)), which is the highest reported value among the reported PANI based ternary composites. The improvement of thermoelectric performance by incorporation of TiO2 suggests a promising approach to enhance power factor of organic thermoelectric materials by judicial tuning of the carrier concentration and electrical conductivity.
在本工作中，我们报道了使用TiO₂/碳纳米管（CNT）/聚苯胺（PANI）三元复合材料制备高性能热电材料。我们表明，二元CNT（70%）/PANI（30%）复合材料的电导率可达约2730 S cm⁻¹，这是所报道的CNT/PANI复合材料的最高记录值。我们进一步证明，通过将TiO₂纳米颗粒掺入二元CNT/PANI复合材料中，可以提高CNT/PANI复合材料的塞贝克系数，这可归因于较低的载流子密度以及低能载流子在TiO₂/a-CNT和TiO₂/PANI界面处的能量散射。所得的TiO₂/a-CNT/PANI三元体系表现出更高的塞贝克系数和增强的热电功率。通过水处理和调整加工温度实现了热电功率的进一步优化。对于30%TiO₂/70%（a-CNT（70%）/PANI（30%））的三元复合材料，获得了114.5 μW mK⁻²的高热电功率因子，这是所报道的基于PANI的三元复合材料中报道的最高值。通过掺入TiO₂来改善热电性能，为通过合理调节载流子浓度和电导率来提高有机热电材料的功率因子提供了一种有前景的方法。
